I have created an issue on onbasca about this problem. It seems that onbasca is failing to test many bridges: https://gitlab.torproject.org/tpo/network-health/onbasca/-/issues/171
Quoting alertmanager@hetzner-nbg1-02.torproject.org (2024-05-28 11:25:59)
Total firing alerts: 1 Total resolved alerts: 0
## Firing Alerts
Time: 2024-05-28 09:25:29.934 +0000 UTC Summary: Too many bridges are rejected Description: The fraction of accepted bridges by their ratio is too low for rdsys
##Resolved Alerts